The appointment of Jeh Johnson to lead the Department of Homeland Security (DHS) signals a different emphasis for the agency.

With this appointment, President Obama replaces an ex-governor of a border state, Janet Napolitano, whose knowledge was fundamentally immigration, with someone he trusts. Johnson is an attorney and in addition to being one of the president's campaign donors, was legal adviser for the Pentagon on the administration's antiterrorist drone war.

It is not clear yet how Johnson, who has no experience on immigration, will contribute to moving forward immigration reform—which is one of the White House's priorities until the end of the year.

However, it is true that DHS is about much more than immigration. This is a giant bureaucratic umbrella with 22 federal agencies, 240,000 employees and a budget surpassing $45 billion. Managing an organization of this size—with 18 key vacancies—will be a big challenge for Johnson, who lacks this kind of experience.

We are concerned that this appointment may not mean any changes to the disastrous handling of the Secure Communities program or to the cruel deportation policy that will soon reach 2 million deportees in five years of the Obama administration. The ongoing separation of families as a result of the poor implementation of a program intended to target dangerous undocumented immigrants must stop once and for all.

Johnson, if confirmed by the Senate, will have his hands full with complex issues. We expect that the implementation of a fairer immigration policy is among them. Let's not forget that border security is not at odds with treating the undocumented in a humane way. Moreover, updated laws like immigration reform actually reinforce national security.